Persistence

Since workflows are typically long running processes, they will need to be persisted to storage between steps. There are several persistence providers available as separate Nuget packages.

• MemoryPersistenceProvider (Default provider, for demo and testing purposes)
• MongoDB
• SQL Server
• PostgreSQL
• Sqlite
• Amazon DynamoDB
• Cosmos DB
• Azure Table Storage
• Redis
• Oracle

Implementing a custom persistence provider

To implement a custom persistence provider, create a class that implements IPersistenceProvider interface:

public interface IPersistenceProvider : IWorkflowRepository, ISubscriptionRepository, IEventRepository, IScheduledCommandRepository
{        
    Task PersistErrors(IEnumerable<ExecutionError> errors, CancellationToken cancellationToken = default);
    void EnsureStoreExists();
}

The IPersistenceProvider interface combines four repository interfaces:

IWorkflowRepository

Handles workflow instance storage and retrieval:

• CreateNewWorkflow - Create and store a new workflow instance
• PersistWorkflow - Update an existing workflow instance
• GetWorkflowInstance - Retrieve a specific workflow instance
• GetRunnableInstances - Get workflow instances ready for execution

IEventRepository

Manages workflow events:

• CreateEvent - Store a new event
• GetEvent - Retrieve a specific event
• GetRunnableEvents - Get events ready for processing
• MarkEventProcessed/Unprocessed - Update event status

ISubscriptionRepository

Handles event subscriptions:

• CreateEventSubscription - Create new event subscription
• GetSubscriptions - Query subscriptions for events
• TerminateSubscription - Remove a subscription
• SetSubscriptionToken/ClearSubscriptionToken - Manage subscription locking

IScheduledCommandRepository

For future command scheduling (optional):

• ScheduleCommand - Schedule a command for future execution
• ProcessCommands - Execute scheduled commands
• SupportsScheduledCommands - Indicates if provider supports this feature

Once implemented, register your provider:

services.AddWorkflow(options => 
{
    options.UsePersistence(sp => new MyCustomPersistenceProvider());
});